Electromagnetic contactor having cam means for operating auxiliary switch



March 25, 1969 Q R MlKOLlC ET Al. 3,435,389

ELECTROMAGNETIC CONTACTOR HAVING CAM MEANS FOR OPERATING AUXILIARYSWITCH Filed April 19, 1967 Sheet March 25, 1969 c. R. MIKOLIC ET AL3,435,389

ELECTROMAGNETIC CONTACTOR HAVING CAM MEANS FOR OPERATING AUXILIARYSWITCH nled Aprll 19 1967 sheet 5 of 2 987311K' 62a 62a X United StatesPatent Oiiice 3,435,389 Patented Mar. 25, 1969 U.S. Cl. 335-121 34Claims ABSTRACT F THE DISCLOSURE An electromagneitc contactor having acontact carrier provided with an inclined plane camming slot and anauxiliary switch having floating contacts operated by a cam followermovable perpendicular to the operating direction of the contact carrierto eliminate the reaction force of the auxiliary switch on .theelectromagnet in the operated position.

This invention relates to electromagnetic contactors and in particularto such contact-ors having a set of main contacts for opening andclosing a power circuit and additional auxiliary contacts for making andinterrupting control circuits of the contactor.

Electromagnetic contactors have main contacts which carry the loadcurrent of the motor or other device being controlled and are oftenprovided with one or more auxiliary, or control, switches. The auxiliaryswitches are interposed in the control circuit of the contactor, or inthe control circuit of a related controller, and generally serve aninterlocking function to insure a desired sequence of contactoroperation. The auxiliary switches for dilerent contactors have varyingarrangements of normally open and normally closed contacts and returnsprings to hold the normally closed contacts in engagement when thecontactor is not energized. The electromagnet of the contactor must becapable of exerting' suilicient force to operate the main contacts andto increase the loading of the auxiliary switch return springs and tooperate the auxiliary switch contacts and hold them engaged underrelatively high pressure contact. The force required to hold theauxiliary contacts engaged varied with the contact arrangement of theauxiliary switch. Consequently the electromagnet of prior art contactorshad to be sufficiently large to h-old the main and auxiliary switchcontacts operated for the embodiment having the largest number of setsof auxiliary contacts, thereby requiring the electromagnet to beunnecessarily large for other embodiments and resulting in a differentoperating characteristic when the auxiliary contact arv rangement waschanged.

It is an object of the invention to provide an electromagnetic contactorhaving an auxiliary switch wherein the electromagnet is not required toexert a force to maintain the auxiliary contacts operated, therebypermitting the electromagnet to 'be of smaller size than in prior artdevices.

It is a further object of the invention to provide such anelectromagnetic contactor wherein the force which the electromagnet mustexert to operate the auxiliary switch is considerably smaller than inprior art devices.

Another object is to provide such an electromagnetic contactor whoseoperating characteristics remain essentially constant regardless of thecontact arrangement of the auxiliary switch or the number of auxiliaryswitches operated by it.

A still further object is to provide an electromagnetic contactorauxiliary switch which provides a different contact arrangement by merereversal of the mounting position of the auxiliary switch on thecontactor housing and without rearrangement of the auxiliary switchcontacts or other components.

These and other objects and advantages of theinvention will be morereadily apparent from the following detailed description when consideredin conjunction with the accompanying drawing wherein:

FIG. l is an exploded side view, partly in section, of theelectromagnetic contactor of the invention having an auxiliary switch;

FIGS. 2 and 3 are views taken along lines II-II and III-III respectivelyof FIG. l;

FIGS. 4 and 5 are lpartial views showing the normal and operatedpositions respectively of the cam means on the main contact carriedrelative to the ca-m follower operating pin of the auxiliary switch;

FIG. 6 is a front view of the cam means of an alternative embodiment ofthe contact adapted to actuate a plurality of auxiliary switches on eachof the opposed sides of the contact housing;

FIG. 7 is a perspective view of the auxiliary switch of the invention;

FIG. 8 is a side view of the auxiliary switch of FIIG. 7;

FIG. 9 is a view taken along line IX-IX of FIG. 8;

FIGS. l0 and 11 are views taken along lines X-X and XI-XI respectivelyof FIG. 9;

FIGS. 12a and 12by show the normal and operated positions respectivelyof an auxiliary switch embodiment having two sets of normally opencontacts, vthe positions of the actuating cam slot being shown in dottedlines;

FIGS. 13a and 13b show the normal and operated lpositions respectivelyof the auxiliary switch of FIG. 12 after its mouting position has beenreversed on the contactor housing to thereby reverse the contactarrangement and provide two sets of normally closed contacts;

FIG. 14 illustrates an alternative embodiment of aux iliary switchhaving two sets of normally open and one set of normally closedcontacts;

FIG. l5 is a perspective view of one of the auxiliary switch stationarycontacts;

FIG. 16 is a perspective view of the contact carrier of the auxiliaryswitch; and

FIG. 17 is a cross sectional view through the auxiliary switch.

Referring to FIG. 1 of the drawing, the electromagnetic contactor of theinvention includes an insulating housing 10, a movable contact assembly11 reciprocable within housing 10, and an insulating cover 12 for thehousing 10 substantially as disclosed in U.S. Patent 3,259,702 toLawrence A. Burton and Gustav W. Doos, having the same assignee as thisinvention and to which reference is made for details of construction.Housing 10 is generally of box shape and is preferably molded ofsuitable insulating material such as gla-ss polyester to have a bottomwall 14 and pairs of opposed sidewalls 16 and 17. Internally threadedmetallic inserts (not shown) may be molded within housing -bottom wall14 to permit mounting of the contactor on Ia vertica-l wall of a switchenclosure. Housing 10 is open at the top to receive movable contactassembly 11 and a coil 18 which is preferably encapsulated in athermosetting resin. Movable contact assembly 1-1 includes a maincontact carrier 20 generally of inverted U-shape having spaced apartlegs 21 (only one of which is shown in FIG. 1) aixed by an elongated bar24 to an E-shaped lamina-ted, movable magnetic armature 22 disposedbetween the legs 21. Elongated bar 24 protrudes through apertures inlegs 21 and armateur 22. Main contact carrier 20 supports a plurality ofmovable flat elongated metallic bridging contacts 25 (only one of whichis seen in FIG.V1) carrying raised button contacts 26 at both endsthereof.

Housing has guideways 28 (see FIG. 2) in sidewalls 17 which slidablyreceive legs 21 of main contact carrier 20 and guide movable contactassembly 1-1 as it reciprocates within housing 10 toward and away fromcover 12. Coil 18 may rest upon the upper ends (not shown) of theportions of housing 10 which define the guideways 28.

Removable cover 12 is preferably molded of the same insulating materialas housing 10 and fits over and closes the open top of housing 10. Cover12 has a generally flat portion 29 upon which two spaced apart rows ofelongated flat metallic stationary contacts 30 are secured by screws 32so that each stationary contact 30 in one set is in alignment with astationary contact 30 in the other set. The inner end of each stationarycontact 30 has a contact button 34 which is adapted to engage thecontact button 26 at one end of movable bridging con tact 25 when maincontact carrier 20 is actuated toward cover 12 by energization of coil18, thereby bridging movable contact 25 rbetween aligned stationarycontacts 30 on cover 12. Inwardly extending barriers 37 molded on cover12 extend between the pairs of aligned sta tionary contacts 30 andprotrude into grooves (not shown) in housing 10 when cover and housingare mated.

Terminals 39 for the stationary main contacts 30 are provided on housing10, and electrical connections between terminals 39 on housing 10 andstationary contacts 30 on cover 12 are completed through plug-in typeconnectors formed by a pair of upstanding, spaced apart ears 40 on eachterminal (only one of which can be seen in FIG. l) defining the femalepart of the plug-in connector and the fiat end 42 of each stationarycontact 30 opposite contact button 34 which is the male part of theplug-in connector and is adapted to protrude with a squeeze fit betweenthe spaced ears 40 when cover 12 and housing 10 are mated. Each terminal39 is provided with a screw 44 for clamping a conductor. With suchconstruction both the movable main contacts 25 and the stationary maincontacts 30 are readily accessible for inspection and replacement whencover 12 is removed from housing 10. Along opposed sidewalls 17 housing10 is provided with cutout portions 45 that mate with generallyU-shapedprojections 46 on cover 12.

A stationary, E-shaped laminated magnetic core member 47 rests upon coil18 so that the middle core leg (not shown) extends through a centralwindow (not shown) in coil 18. When cover 12 is assembled onto housing11 and secured thereto -by screws 48, resilient members 49 on barriers37 push against stationary core member 47 so that it presses coil 18against support portions of housing 10 and prevents movement of coil 18and core members 47 relative to housing 10. Springs 50 on cover 12engage laterally extending arms 53 on main contact car- -rier 20 whencover 12 is assembled to housing 10 and normally hold movable contactassembly 11 in its lowest position wherein movable main contacts 25 Iaredisengaged from stationary contacts 30. Coil 18, stationary magneticcore member 47, and movable armature 22 form the elect-romagnet of thecontactor.

In the preferred embodiment of the invention, each leg 21 of contactcarrier 20 has a protuberance defining an inclined plane cam slot 55therein, and sidewalls 17 of housing 10 have square auxiliary switchmounting openings 56 therein opposite cam slots 55 into which anauxiliary switch 58 may be assembled in either of two alternatepositions so that a cam follower pin 59 for operating the auxiliaryswitch contacts fits into cam slot 55. Auxiliary switch 58 has differentarrangements of normally open and normally closed contacts in thealternate positions. Housing 10 has wa-ll portions 60 perpendicular tosidewalls 17 which partially define auxiliary switch mounting opening 56and which have hook-shaped protrusions `61 (see FIG. 3) into whichprojecting ears 62b on auxiliary switch 58 fit. Mounting screws 64extending through clearance holes in a projecting shelf portion 65 onhousing sidewall 17 which partially defines opening 56 may be threadedwithin metallic inserts molded within casing 70 of auxiliary switch 58to support auxiliary switch 58 on contacter housing 10.

The movable contacts 85 (see FIGS. ll-14) of auxiliary switch 58 aresupported by an auxiliary contact carrier 88 which floats within theauxiliary casing 70 and is integral with cam follower pin 59, and camfollower pin 59 normally occupies a position in the bottom of cam Slot55, shown in FIG. 4, wherein the camming surfaces 71 are parallel to thedirection of movement of main contact carrier 20 and the auxiliaryswitch contacts are thus normally held in position by the main contactcarrier 20. Energization of coil 18 attracts movable magnetic armature22, and main contact carrier 20 axed thereto, toward stationary coremember 47, whereby the inclined plane cam slot 55 actuates cam followerpin 59 from the position shown in FIG. 4 to that shown in FIG. 5 as thelegs 21 of contact carrier 20 slide in guideways 28 in contacter housing10. It will be noted that the cam means defined by cam slot 55 and campin 59 is of the positive motion type and that the cam follower pin 59is actuated by cam slot 55 in a direction perpendicular to the directionof movement of legs 21 of contact carrier 20. The mechanical advantageprovided by the inclined plane camming slot 55 minimizes the force whichthe electromagnets must provide to operate the auxiliary switchcontacts. It will also be noted that cam follower pin 59 is positivelyconstrained in both the normal and operated positions of the maincontact carrier 20 shown in FIGS. 4 and 5 respectively, and cammingsurfaces 72 parallel to the direction of reciprocation of main contactcarrier 20 and adjacent the open end of cam slot 55 enable the maincontact carrier 20 to hold the auxiliary switch contacts in operatedposition without any reaction force exerted in the direction that themain contact carrier 20 is reciprocated, thereby eliminating thenecessity for the electromagnet to hold the auxiliary switch contactsoperated and permitting substantial reduction in the size of theelectromagnet.

This feature will be better appreciated with an understanding of thefloating contact construction of the auxiliary switch 58 which will nowbe described. Auxiliary switch casing 70 is preferably a right angleprism, i.e., generally of box-shape, and preferably is molded of asuitable transparent insulating material such as polycarbonate to permitvisual determination of the auxiliary switch contact arrangement. Acover 73 of similar material closes the open end of casing 70. Auxiliaryswitch casing 70 has two pairs of mounting ears 62a and 62h (see FIG. 7)described hereinbefore extending from opposite sidewalls thereof. Sixelongated holes 75 in the bottom wall 74 of casing 70 communicate withthe interior of casing 70 and are counterbored (see FIG. 17) to receivemetallic stationary contacts 76 so that one flat portion 77 of eachstationary contact 76 protrudes from casing 70 and forms a wiringterminal and the other -iiat portion 79 is upstanding within casing 70and carries contact buttons 81. The two flat portions 77 and 79 ofstationary contact 76 are disposed at an angle to each other (see FIG.15) and form a shoulder which is received within the counterbore of ahole 75 to prevent removal of stationary contact 76 through elongatedhole 75. The six stationary contacts 76 are arranged in three pairs withthe stationary contacts of each pair being disposed on opposite sides ofan auxiliary contact carrier 88 of insulating material integral with camfollower pin 59.

I-shaped movable metallic auxiliary bridging contacts having contactbuttons 86 at both ends thereof may be supported on the auxiliarycontact carrier 88 and are adapted to engage the contact buttons 81 andbridge between a pair of auxiliary switch stationary contacts 76.Auxiliary contact carrier 88 is generally of box shape (see FIG. 16) andis freely slidable within an elongated guide slot 89 (see FIGS. 9, l0and 17) in the bottom wall 74 of casing 70. A pair of rectangular crosssection openings 90 (see FIGS. 14 and 16) extend laterally throughauxiliary contact carrier 88, and the lI-shaped movable auxiliarybridging contacts 85 extend through openings 90 and are held on carrier88 by compression springs 92 (see FIGS. 1l and 14) disposed within therectangular openings 90 and urging the I-shaped contacts against thelaterally extending walls defining the rectangular openings 90 inauxiliary contact carrier 88. A bridging contact 85 may be held by acompression spring 92 against either of the opposed laterally extendingwalls defining rectangular opening 90, thereby permitting variation ofthe auxiliary switch contact arrangement.

Auxiliary switch cover 73 (see FIGS. 11 and 17) tits over and closes theopen end of casing 70 and has an elongated slot 94 which receives camfollower pin 59 and permits auxiliary contact carrier 88 to bereciprocated within guide slot 819 in casing bottom wall 74 by cammingslot 55. The cover 73 also has indentations (see FIG. 17) which receiveand support the ends 79 of auxiliary stationary contacts 76. Preferablycover 73 also has an elongated guide slot 95 (see FIG. 17), similar toslot 89 in bottom wall 73, for guiding auxiliary contact carrier 88 in adirection in quadrature with the direction of movement of main contactcarrier 2G'. Cover 73 may be secured to casing 70 by headed rivets 96(see FIGS. 9 and 17) of suitable thermoplastic material which extendthrough clearance apertures in these members and have the reduceddiameter end deformed by heat and pressure.

Auxiliary switch S8 may be provided with three sets of double breakcontacts in any desired normally open or normally closed arrangement -bymerely varying the stationary contacts 76 inserted in the elongatedholes 75 and the movable bridging contacts 85 assembled through therectangular openings 90 in auxiliary contact carrier 88. FIG. 12a showsan auxiliary switch having two sets of double break, normally opencontacts formed by four stationary contacts 76 extending through holes75 and cooperating with two I-shaped movable bridging contacts 85mounted on carrier 88. In the normal position shown in FIG. 12a, maincontact carrier 20I is at its lowermost position and camming surface 71of cam slot 55 holds cam follower pin 59 in a position at the left endof its travel, wherein the contact buttons `86 on movable contacts 85are disengaged from button contacts 81 on stationary contacts 76. In theoperated position of this contactor shown in FIG. 12b, main contactcarrier 20 has been actuated to its operated position and cam slot S5has operated cam follower pin 59 to the right until contact buttons 86on movable auxiliary bridging contacts 85 are urged against contactbuttons 81 on stationary contacts 76. In the operated switch positionshown in FIG. 12b, the compression springs 92 are partially loaded tomaintain high pressure contact between stationary contacts 76 andmovable bridging contacts 85, but such pressure is perpendicular to thedirection of movement of main contact carrier and consequently thecontactor electromagnet is not required to exert any force to hold theauxiliary contacts 76 and 85 engaged. In other words, the auxiliaryswitch movable contacts 85 are held in engaged position by cam followerpin 59 engaging camming surface 72 of cam slot 55 parallel to thedirection of movement of main contact carrier 11.

The auxiliary contact carrier 88 supporting movable auxiliary contacts85 constitutes a free floating contact assembly which is directly andpositively controlled at all times by cam follower pin 59 engaged withincamming slot 55, and the normal and closed positions of auxiliarycontact carrier 88 are established by the position of main Contactcarrier 20. Further, all reaction force from the auxiliary switchcontacts in the direction of movement of main contact carrier 20 iseliminated in the normal and operated positions of the contactor,thereby providing a constant load on the electromagnet in the operatedposition regardless of the contact arrangement of the auxiliary switch.

FIG. 13a: illustrates the auxiliary contact arrangement after themounting position of auxiliary switch 58 of FIG. l2 has been reversed oncontactor housing 10. It will be noted that the auxiliary switch of FIG.12a has two normally open sets of double break contacts, whereas thesame switch has two sets of normally closed contacts, as shown in FIG.13a, after its mounting position on contactor housing 10 has beeninverted. Further, such different auxiliary switch contact arrangementdoes not require rearrangement or reassembly of the auxiliary switchcontacts. The reversal of the mounting of auxiliary switch 58 to providea ditferent arrangement of contactsl merely requires loosening of screws`64, removal of auxiliary switch 58 from contactor housing 10, turningthe switch 180, and assembling it on housing 10 so that mounting ears62a (see FIG. 7) rather than ears 62btit beneath hook-shaped portions 61on housing 10', and again securing switch 58 to housing 10 by means ofscrews 64. Camming surface 71 of cam slot 55 normally holds cam followerpin 59 in a position wherein contact buttons 86 on movable auxiliarycontacts normally engage and bridge contact buttons 81 on stationarycontacts 76 as shown in FIG. 13a. When contact carrier 11 is actuated tothe operated position by energization of coil 18, cam slotY 55 pushescam follower pin 59 to the right as seen in the drawing and disengagesmovable contacts 85 from stationary contacts 76 as shown in FIG. 13b.The camming surface 72 parallel to the direction of motion of maincontact carrier 20 holds cam follower pin -59 and carrier 88 in theoperated position so that the electromagnet need exert no force tomaintain the movable auxiliary contacts 85 in their actuated position.

FIG. 14 illustrates an embodiment wherein auxiliary switch 58 has twonormally closed and one normally open set of double break contacts. Inthis embodiment two I- shaped movable bridging contacts 85 protrudethrough the same rectangular opening in the auxiliary contact carrier 88and are urged against opposite walls of opening 90 by compression spring92. Reversal of the mounting position of the FIG. 14 auxiliary switchembodiment on contactor housing 10 changes the two normally closed andone normally open sets of auxiliary contacts into two sets of normallyopen and one set of normally closed auxiliary contacts, and such changeof contact arrangement is accomplished without moving any of the switchcontacts or other components. Other embodiments of auxiliary switch 58can have one set of normally open and one set of normally closedauxiliary contacts or only one set of auxiliary contacts as desired, andsuch auxiliary contact arrangements are reversed when the mountingposition of casing 70 on auxiliary housing 10 is inverted.

The cam slot 55 is open adjacent camming portion 72, thereby permittingwithdrawal of main contact carrier 20 from housing 10 for repair andinspection without interference between the cam slot 55 and the camfollower pin 59, and also permitting reinsertion of main Contact carrier20 into housing 10 without removing auxiliary switch 58 from housing 10.

As best shown in FIG. 7, cover 73 of auxiliary switch 58 has fourprotruberances 98 at the corners thereof delining slots A, B, C and DIwhich provide access to cam follower pin 59 and allow operation of theauxiliary switch contacts from any one of four different directions. Thealigned slots B and D receive leg 21 of main contact carrier 20, whereasaligned slots A and C are narrower than slots B and D and will not fitover leg 21 and thus prevent improper orientation of auxiliary switch5'8 when assembled on contactor housing 10.

In this preferred embodiment of the invention each leg 21 of maincontact carrier 20 has a cam slot 55 for operating an auxiliary switch58. In the embodiment of FIG. 6 each leg 21 of the main contact carrier20 has a cam slot 55 which receives the cam follower pins 59' on twoauxiliary switches and operates both auxiliary switches `as the maincontact carrier 20 is moved toward the contactor cover. In suchembodiment the size of the auxiliary switch mounting opening shown at 56in FIG. l is increased to accommodate the two auxiliary switches.

Although the preferred embodiment of the invention has Ibeen describedas having cam means of the cam slot and cam follower pin type with themain contact carrier having the cam surface, it will be appreciated thatthe invention is not so limited and also comprehends other forms of cammeans as well as an arrangement wherein the cam pin is carried by themain contact carrier and is a driving element rather than a follower.

While only a few embodiments of the invention have been illustrated anddescribed, many modifications and variations thereof will be readilyapparent to those skilled in the art, and consequently it is intended inthe accompanying claims to cover all such modifications and variationswhich are within the true sprit and scope of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. An electromagnetic contactor having stationary and movable maincontacts, a main contact carrier supporting said movable main contactsand being reciprocable in a direction to engage them with and disengagethem from said stationary main contacts, electromagnetic means foractuating said main contact carrier, stationary and movable auxiliarycontacts, cam means responsive to reciprocation of said main contactcarrier for operating said auxiliary contacts between open and closedposition including a first member having an inclined plane cam surfacedisposed at an oblique angle to said direction of reciprocation of saidmain contact carrier and a second member engaging said cam surface, oneof said members being carried by said contact carrier and the otherbeing operatively connected to said movable auxiliary contact, wherebythe mechanical advantage provided by said inclined plane cam surfacereduces the force which said electromagnetic means must provide tooperate said auxiliary contacts.

2. An electromagnetic contactor in accordance with claim 1 wherein saidmain contact carrier is integral with said first member having saidinclined plane cam surface and said second member `is a cam followerpin.

3. An electromagnetic contactor in accordance with claim 1 and includingan insulating auxiliary contact carrier supporting said movableauxiliary contact and operatively connected to said other member andwherein said auxiliary contact carrier and said other member areoperated by said cam means in a transverse direction perpendicular tosaid direction of reciprocation of said main contact carrier.

4. An electromagnetic contactor in accordance with claim 1 wherein saidcam means is of the positive motion type and said cam surface has aportion parallel to said direction of reciprocation of said main contactcarrier which engages said second member when said main contact carrieris actuated to its operated position by said electromagnetic means,whereby said auxiliary contacts are held operated without exerting areaction force opposing said electromagnetic means.

5. An electromagnetic contactor in accordance with claim 3` wherein saidcam surface is a cam slot having opposed wall portions adjacent one endthereof parallel to said direction of reciprocation of said main contactcarrier and wherein said second member is a cam pin constrained withinsaid slot and held between said opposed wall portions adjacent said oneend when said main contact carrier is reciprocated to its operatedposition by said electromagnetic means.

6. An electromagnetic contactor in accordance with claim 5 wherein saidmain Contact carrier has said cam slot and said cam pin is a camfollower and is constrained within said cam slot.

7. An electromagnetic contactor in accordance with claim 6 and includingmeans for guiding said auxiliary contact carrier in said transversedirection.

8. An electromagnetic contactor in accordance with claim 3 and includingan auxiliary switch having aninsulating casing enclosing said auxiliarycontacts and said auxiliary contact carrier and said casing has guideslot means in one wall thereof elongated in said transverse directionfor guiding said auxiliary contact carrier as it is operated in saidtransverse direction.

9. An electromagnetic contactor in accordance with claim 3 wherein saidcam surface has portions adjacent both its ends parallel to saiddirection of reciprocation of said main Contact carrier member one ofwhich normally engages said second member and the other of which engagessaid second member when said main contact carrier is actuated to itsoperated position by said electromagnetic means, whereby said auxiliarycontacts do not exert a reaction force on said main contact carrier inthe normal and operated positions of said contactor.

10. An electromagnetic contactor in accordance with claim 9 wherein saidmain contact carrier is integral with said first member having said camsurface and said second member is a cam follower pin.

11. An electromagnetic contactor in accordance with claim 10 whereinsaid cam surface is a cam slot restraining said cam follower pin andsaid portions adjacent both ends of said cam surface are opposed wallportions of said cam slot and said cam slot is open adjacent said otherportion of said cam surface and permits said cam follower pin to leavesaid cam slot without interference as said main contact carrier is movedin said direction of reciprocation, whereby said `main contact carriermay easily be removed for inspection and repair.

12. An electromagnetic contactor having stationary and movable maincontacts, a main contact carrier supporting said movable main contactsand operable in a direction to engage said movable main contacts withand to disengage them from said stationary main contacts and having aninclined plane camming surface at an oblique angle to said direction ofoperation, a cam follower engaging said camming surface, an auxiliaryswitch having stationary and movable auxiliary contacts and an auxiliarycontact carrier operatively connected to said cam follower and carryingsaid movable auxiliary contact and being operable in a directi-onperpendicular to said direction of operation of said main contactcarrier to engage said movable auxiliary contacts with and disengagethem from said stationary auxiliary contacts, and electromagnetic meansfor operating said main contact carrier, whereby the mechanicaladvantage of said inclined plane camming surface reduces the force which`said electromagnetic means must exert to actuate said auxiliary switchand hold it operated.

13. An electromagnetic contactor comprising an insulating housing havinga` guideway therein, stationary main contacts on said housing, mov-ablemain contacts, a main contact carrier supporting said movable maincontacts and Ibeing reciprocable in said guideway to engage said movablemain contacts with and disengage them from said stationary maincontacts, an electromagnet including an electric coil and a stationarymagnetic core element affixed within said housing and an armatureaffixed to said main contact carrier and being attracted toward saidstationary core element upon energization of said coil to operate saidmain contact carrier, an auxiliary switch mounted on said housingincluding stationary Aand movable auxiliary contacts, and cam meansresponsive to reciprocation of said m-ain contact carrier to engage saidmovable auxiliary contact with and disengage it from said stationaryauxiliary contact and including a irst member having a cam surfacedisposed at an oblique angle to said direction of reciprocation of saidmain contact carrier and a second member engaging said cam surface,

one of said members being carried by said main contact carrier and theother being operatively connected to said movable auxiliary contact,whereby the mechanical advantage of said inclined plane camming surfacereduces the force which said electromagnet -must exert to operate saidauxiliary switch.

14. An electromagnetic contactor in accordance with claim 13 whereinsaid main contact carrier is integral with said first member having saidcam surface and said second member in a cam follower pin.

15. An electromagnetic cont-actor in accordance with claim 13 whereinsaid cam surface positively controls said second member and has portionsat both its ends parallel to said direction of reciprocation of saidmain contact carrier one of which normally engages said second memberand the other of which engages said second member when said main Contactcarrier is actuated to its operated position by said electromagnet,whereby said auxiliary contacts exert no force in the direction ofreciprocation of said main contact carrier in the normal and operatedcontactor positions.

16. An electromagnetic contactor in accordance with claim 13 whereinsaid auxiliary switch includes an insul-ating auxiliary contact carriersupporting said movable auxiliary contact and being operativelyconnected to said other member and wherein said other member and saidauxiliary contact carrier are operated in a transverse directionperpendicular to said direction of reciprocation of said main contactcarrier.

17. An electromagnetic contactor in accordance with claim 15 whereinsaid main contact carrier has said cam surface and said second member isa cam follower pin and said cam surface is -a cam slot receiving saidcam follower pin and said portions at both ends of said cam surfaceparallel to said direction of reciprocation of said main contact carrierare opposed wall portions of said cam slot which constrain said cam -pinwhen said main contact carrier is in its normal and operated positions.

18. An electromagnetic contactor in accordance with claim 13 whereinsaid guideway is defined by spaced p0rtions of said insulating housingproviding an aperture therebetween and said second member is a cam pinand extends through said apertures.

19. An electromagnetic contactor in accordance with claim 17 whereinsaid guideway is defined by spaced portions of said insulating housingproviding an aperture therebetween and said cam slot in said maincontact carrier member is accessible through said aperture and said campin extends through said aperture.

20. An electromagnetic contactor in accordance with claim 19 whereinsaid cam slot is open adjacent said other portion of said cam surfaceand permits said cam pin to leave said cam slot without interference assaid main contact carrier is moved in said guideway.

21. An electromagnetic contactor in accordance with claim 16 whereinsaid auxiliary switch includes a hollow insulating casing enclosing saidstationary and movable auxiliary contacts and said auxiliary contactcarrier and also including means for removably mounting said -auxiliaryswitch casing on said contactor housing in either of two alternatepositions wherein the auxiliary -contact arrangement in one position isreversed from that in the other position.

22. An electromagnetic contactor in accordance with claim` 21 whereinsaid casing has guide slot means therein for guiding said auxiliarycontact carrier during movement and said casing mounting means supportssaid casing in both of said two alternate positions so that said guideslot means directs said auxiliary contact carrier in said transversedirection perpendicular to said direction of reciprocation of said maincontact carrier.

23. An electromagnetic contactor in accordance with claim 22 whereinsaid cam' means is of the positive motion type and has portions at bothits ends parallel to said direction of reciprocation of said maincontact carrier one of which normally engages said second member and theother of which engages said second member when said main contact carrieris actuated to its operated position and wherein said auxiliary contactcarrier is operatively connected` to said second member rby meansextending freely through a `Wall of said casing.

24. An electromagnetic contactor in accordance with claim 23 whereinsaid first member having `said cam surface is integral with said maincontact carrier and said cam surface is a cam slot and said secondmember is a cam follower pin constrained within ysaid cam slot.

25. An electromagnetic contactor in accordance with claim 24 whereinsaid contactor housing has a recess complementary to said auxilaryswitch casing which removably receives said auxiliary switch casing andconstitutes said means for mounting said casing on said housing ineither of said two alternate positions.

26. An electromagnetic contactor in accordance with claim 19 whereinsaid auxiliary switch casing is a right angle prism and said contactorhousing has a .rectangular recess therein in register with said apertureand cornplementary to and adapted to removably receive said auxiliaryswitch casing in either of two alternate positions wherein said cam pinengages said cam slot and the auxiliary switch contact arrangement inone of said two alternate positions is reversed from that in the otherposition.

27. An electromagnetic contactor in accordance with claim 16 whereinsaid auxiliary switch'includes a hollow insulating casing of rightrect-angular prism configuration enclosing said auxiliary contacts andsaid auxiliary c011- tact carrier and having elongated guide slot meanstherein for guiding said auxiliary contact carrier during -movementthereof and said contactor housing has a rectangular recess thereincomplementary to and adapted to receive said auxiliary switch casing ineither of two -alternate positions so that the longitudinal axis of saidelongated guide slot means is in said transverse direction and saidauxiliary switch has different arrangements of said stationary andmovable auxiliary contacts in said alternate positions.

Z8. An electromagnetic contactor in accordance with claimI 27 whereinsaid first member having said cam surface is integral with said maincontact carrier and said cam surface is a cam follower pin constrainedwithin said cam slot.

29. An electromagnetic contactor in accordance with claim 25 whereinsaid auxiliary contact carrier floats freely within said casing and isheld in its normal and operated positions by said opposed wall portionsof said cam slot adjacent both ends of said cam slot extending parallelto said direction of reciprocation of said main contact carrier.

30. An electromagnetic contactor in accordance with claim 29 wherein aplurality of pairs of metallic stationary auxiliary contacts areupstanding within said auxiliary switch casing with the stationarycontacts of each pair disposed on opposite sides of said auxiliarycontact carrier and having terminal portions extending through a wall ofsaid casing accessible from the exterior of said casing and wherein saidmovable auxiliary contact is an elongated metallic bridging memberhaving contact buttons adjacent its ends and adapted to engage andbridge between the stationary contacts of at least one of said pairs ofstationary contacts.

31. An electromagnetic contactor in accordance with claim 30, whereinsaid auxiliary contact carrier has an opening of rectangular crosssection therethrough perpendicular to its direction of movement and saidbridging auxiliary contact member protrudes freely through saidrectangular opening and extends on 4both sides of said auxiliary contactcarrier, and including a compression spring within said rectangularopening urging said movable auxiliary contact bridging member againstone wall defining said rectangular cross section opening and supportingsaid auxiliary movable contact bridging member on said auxiliary contactcarrier, whereby said movable auxiliary bridgingl contact may bedisposed against either of a pair of opposed walls of said auxiliarycontact carrier defining said rectangular cross `section opening topermit different arrangements of normally open and n-ormally closedauxiliary switch contacts.

32. An electromagnetic contactor in accordance with claim 26 whereinsaid recess and said casing are of square cross section and saidauxiliary switch casing has means for preventing insertion of Saidcasing into said recess when it is oriented in any position other thansaid two alternate positions.

33. An electromagnetic contactor including an insulating housing havinga recess therein, stationary main contacts on said housing, a maincontact carrier reciprocable within said housing, movable main contactssupported on said main contact carrier, electromagnetic means withinsaid housing for reciprocating said main contact carrier in a directionto engage said movable main contacts with and disengage them from saidstationary main contacts, an auxiliary yswitch having an insulatingcasing removably positioned within said recess, stationary and movableauxiliary contacts within said casing, yand a movable member operativelyconnected to said movable auxiliary contact and adapted when actuated tooperate said auxiliary contacts, said recess being complementary to andadapted to receive said auxiliary switch casing in either of twoalternate orientations wherein said auxiliary switch has differentarrangements of normally open and normally closed auxiliary contacts andmeans responsive to reciprocation of said main contact carrier when saidauxiliary switch is in either of said alternate orientations foractuaing said movable member.

34. An electromagnetic contactor in accordance with claim 33 whereinsaid recess and said casing are of rectangular cross section and saidauxiliary switch provides a rst contact yarrangement lwhen said casingis received in one orientation within said recess and a contactarrangement reversed from said first arrangement when -said casing isreceived within said recess in an orientation inverted from said rstorientation.

References Cited UNITED STATES PATENTS 2,874,244 2/1959 Hamblett 335-1903,192,329 6/1965 Murrle.

3,238,329 3/1966 Russo 335--132 3,324,431 6/1967 Cataldo 335--1323,359,392 12/1967 Heath.

BERNARD A. GILHEANY, Primary Examiner.

HAROLD BROOME, Assistant Examiner.

